WASHINGTON — With just two weeks before the opening of the Olympic Games in Sochi, Russia, there has been an increase in reports of security threats, a senior administration official said Friday.

“We've seen an uptick in threat reporting” based on intelligence and media reports, said the official, who joined representatives from three government agencies to brief reporters in a conference call under rules prohibiting their identification.

“We are aware of reports of potential threats that may occur during the Olympic Games, including the media accounts we've seen of female suicide bombers and a video posted online claiming responsibility for the tragic bombings in Volgograd, that also promised more attacks during the Sochi Games," the official said. "We take all such threats seriously.”

He was referring to Russian police warnings that a female suicide bomber may be in Sochi, with two others also considered a threat. Separately, a video was posted by an Islamic separatist group that claimed responsibility for attacks last month that killed 34 people in Volgograd, about 400 miles northeast of Sochi.

Some 500 U.S. athletes and coaches and 10,000 American spectators are expected at the Games in the Russian resort on the Black Sea, close to the restive North Caucasus region. The official U.S. delegation will be led by former Homeland Security Secretary Janet Napolitano.

Defense Secretary Chuck Hagel said Friday that the U.S. was prepared to evacuate citizens from Sochi in the event of an attack.

“If we need to extract our citizens, we will have appropriate arrangements with the Russians to do this,” Hagel said at a brief news conference at the Pentagon with his French counterpart. The U.S. is planning to send two warships able to provide evacuation and medical care.

Officials at the news briefing downplayed reports of discussions between the U.S. and Russian militaries about the U.S. providing technology it developed in Iraq and Afghanistan to detect homemade bombs. There has been no Russian request for such technology at the Olympics or any American offer, they said.

Obama administration officials largely ducked questions about complaints from Congress that Russia was not providing the U.S. with enough intelligence about the possible threats at the Games.

“Now, of course, we always wish our partners will share more information with us,” said one official who admitted to some frustration that the U.S. does not know more about what is going on.

“And obviously, we have closer cooperation with countries such as the UK than we do -- with a partner like Russia or probably with China,” the official said.